12 Keyword substitution

As long as you edit source files inside a working
directory you can always find out the state of
your files via ‘cvs status’ and ‘cvs log’.
But as soon as you export the files from your
development environment it becomes harder to identify
which revisions they are.

CVS can use a mechanism known as keyword
substitution (or keyword expansion) to help
identifying the files. Embedded strings of the form
$keyword$ and
$keyword:...$ in a file are replaced
with strings of the form
$keyword:value$ whenever you obtain
a new revision of the file.